1. Field of the Invention
The present invention relates to an apparatus for removing iron powder from rolling oil and, more particularly, to an improved apparatus for removing iron powder from rolling oil, which can reduce troubles and facilitate maintenance with a simple construction while greatly improving efficiency in separation of iron powder, which can cause serious defects to the quality of products and concerned facilities.
2. Description of the Prior Art
In general, cold-rolled steel sheets with a uniform thickness and a smooth surface are used for bodies of automobiles, measuring devices, electrical appliances, and the like. Such cold-rolled steel sheets are produced by acid-pickling and rolling hot-rolled steel plates through rolls of a cold rolling mill. In this manufacturing process, rolling oil is used for cooling, lubricating and rust-protecting of the rolls of the rolling mill. Since the rolling oil is pumped from a rolling oil tank and repeatedly used, the rolling oil returning to the rolling oil tank contains fine iron powder, which is generated during rolling. When the iron powder is introduced and accumulated in the oil tank, it contaminates the rolling oil or obstructs the flow of rolling oil, thereby causing malfunction of the rolling mills or defects such as scratches on the surface of a resultant cold-rolled steel sheet. As a result, the quality of a final product is degraded.
In order to prevent the iron powder from collecting inside the oil tank, an apparatus for separating or removing the iron powder from the rolling oil has been developed. One example of the conventional apparatus will be briefly described with reference to the drawing. Referring to FIG. 1, a conventional apparatus 1 for removing iron powder includes a conveyor belt 2 extending to pass through a rolling oil tank 5, a plurality of magnets 3 disposed on the conveyor belt 2, a scraper 6 located at one side of the conveyor belt 2 to remove iron powder from the magnets 3 having passed through the rolling oil tank 5, and a collection box 7 for collecting the iron powder separated by the scraper 6. In this conventional apparatus 1, the magnets 3 on the conveyor belt 2 are polygonal or round bar-shaped or are linked with each other, and the scraper 6 is provided with a variety of configurations according to the configurations of the magnets 3 so as to separate the iron powder from the surfaces of the magnets 3.
However, in the conventional apparatus 1 using this type of conveyor belt 2 which has a unitarily-linked structure, in the event where part of the conveyor belt 2 malfunctions, inspection and repair cannot be performed until the entire apparatus is suspended, thereby causing an increase in down-time of the apparatus.
Particularly, in the event where the apparatus is stopped due to failure or for repair, since a part of the conveyor belt 2 is in a state of being immersed in the rolling oil tank 5, it is necessary to disassemble the entire apparatus for repairing the part of the conveyor belt 2 immersed in the rolling oil tank 5. However, such a disassembling operation is inconvenient, and the repair of the part of the conveyer belt 2 is very troublesome.
Furthermore, when the conveyor belt 2 is circulated from the oil tank 5 to an upper portion of the apparatus and then returned thereto, the rolling oil flowing into or being discharged from inside the conveyor belt 2 can be mixed with sludge stuck to the conveyor belt 2. Here, the sludge tends to clog the apparatus due to the structural characteristics of the apparatus, thereby causing frequent failure of the apparatus while making it difficult to clean or repair the apparatus. Moreover, since the conveyor belt 2 repeatedly passing through the oil tank 5 is vulnerable to rust resulting from contamination by the iron powder and sludge, the conventional apparatus has a short lifetime.